Inhibition of prolyl hydroxylase by poly(ADP-ribose) and phosphoribosyl-AMP. Possible role of ADP-ribosylation in intracellular prolyl hydroxylase regulation

• Published in: The Journal of biological chemistry 1989-05, Vol.264 (14), p.7850-7855
• Main Authors: ZAMIRUL HUSSAIN, M, PERVEEN GHANI, Q, HUNT, T. K
• Format: Article
• Language: English
• Subjects: Adenosine - analogs & derivatives; Adenosine - pharmacology; Adenosine Diphosphate Ribose - pharmacology; Adenosine Monophosphate - analogs & derivatives; Adenosine Monophosphate - pharmacology; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cell Nucleus - metabolism; Chick Embryo; Enzyme Activation - drug effects; Enzymes and enzyme inhibitors; Fibroblasts - drug effects; Fibroblasts - enzymology; Fundamental and applied biological sciences. Psychology; Hydroxylation; Lactates - pharmacology; Lactic Acid; liver; Liver - metabolism; Mixed Function Oxygenases; NAD - metabolism; nuclei; Nucleoside Diphosphate Sugars - pharmacology; Oxidoreductases; Phosphodiesterase I; phosphoribosyl-AMP; Phosphoric Diester Hydrolases - metabolism; Poly Adenosine Diphosphate Ribose - pharmacology; poly(ADP-ribose); Procollagen - metabolism; Procollagen-Proline Dioxygenase - antagonists & inhibitors; Rabbits; Rats
• ISSN: 0021-9258; 1083-351X

Poly(ADP-ribose) prepared by incubating NAD+ with rat liver nuclei inhibited the hydroxylation reaction catalyzed by purified prolyl hydroxylase (proline,2-oxoglutarate dioxygenase, EC 1.14.11.2) in vitro. Near complete inhibition of the enzyme was seen in the presence of 6 nM (ADP-Rib)18 with a Ki(app) of 1.5 nM. The monomer unit of poly(ADP-ribose), adenosine diphosphoribose (ADP-Rib), was found to be a weak inhibitor. On the other hand, poly(ADP-ribose)-derived phosphoribosyl-AMP (PRib-AMP) and its dephosphorylated product, ribosyl-ribosyl-adenine (Rib-RibA), inhibited the enzyme in nanomolar concentrations (Ki(app) 16.25 nM). The order of inhibition was (ADP-Rib)18 greater than PRib-AMP, Rib-RibA much greater than ADP-Rib. These results suggested that the 1"---2' ribosyl-ribosyl moiety in these compounds was involved in the inhibition of the enzyme. The possibility that intracellular prolyl hydroxylase is regulated by the involvement of ADP-ribosylation reactions was examined in confluent cultures of skin fibroblast treated with 20 mM lactate. The activity of prolyl hydroxylase was stimulated by 145% over that of untreated cultures. In the lactate-treated cells, the level of NAD+ was lowered and the total ADP-ribosylation of cellular proteins reduced by 40%. These observations imply that the lactate-induced activation of cellular prolyl hydroxylase is mediated by a reduction in ADP-ribosylation and that the synthesis and degradation of ADP-ribose moiety(ies) may possibly regulate prolyl hydroxylase activity in vivo.